It is known that chronically ill, people or patients known to suffer from cardiac problems, and patients recovering from a surgical intervention or cardiac episode or a disease use personal ECG devices whether this on regular basis or while they don't feel well. In the prior art there are several ECG devices that can obtain a standard 12 lead ECG, such as clinical ECG machines as well as personal ECG telephonic acoustic devices (e.g., CardioSenC, Cardiobeeper 12L or CardioBeeper 12/12 by SHL Telemedicine). These personal medical ECG devices are adapted to be used by a non-medical individual to capture a 12 lead ECG and/or Rhythm strip when the user has symptoms, routinely, as part of drug studies, pre/post surgery, etc. Although these devices do allow a non medical user to obtain a standard 12 lead ECG and rhythm strip at any time and transfer it to a remote medical data center, no ECG information is available for the user itself and the telephonic transmission acoustic devices are subject to local ambient noise that causes ECG interference.
The standard 12 lead electrocardiogram in clinical use today obtains the electrical activity of 9 monitoring electrodes and developing 12 views of the electrical activity in accordance with the accepted measuring methods as setforth by Einthoven, Goldberger and Wilson. Einthoven defined the Einthoven triangle by measure 3 limb leads consisting of the Right Arm (RA), Left Arm (LA) and Left Leg (LL). Goldberger further suggested the 3 augmented unipolar limb leads of aVR, aVL, and aVF which are measured sequentially by combining two limb leads and measuring the third limb. Wilson devised the summation of the three limb leads and measuring the electrical activity from 6 precordial anatomically positioned chest electrodes creating the views, V1, V2, V3, V4, V5, and V6. It is the use of these 12 leads that define the clinically accepted standard for today's 12 lead electrocardiogram.
Moreover, some of the prior-art personal devices, such as the Cardiosen'C that in addition to acoustic telephonic transmission can communicate with a remote data center directly via its internal cellular modem. However, this takes considerable power thus a large rechargeable battery and charger is also required resulting in a device having relatively large dimensions affecting its portability and less comfortable an unlikely to carry by the user at all times due to their overall dimensions. Therefore, there is also a need for a smaller device than the Cardiosen'C and the other prior-art units that utilize a smaller battery that device is easier to carry and therefore it is more desirable to be carried more often.
For years, many have tried to reduce the number of electrodes applied by placing fewer electrodes and recreating the 12 Lead ECG by calculation. All of these methods have some form of errors when compared to all the 12 Lead ECG from all people. Different anatomical masses, physical positions, changing conditions in the human body, inaccurate or improper electrode positioning together with calculation errors in the algorithms can contribute to errors and poor results. Steps have been taken to minimize errors including those set forth by some of the following prior art publications.
US patent application No. 2006/0111640 of Shen et al discloses an electrocardiogram monitoring device that utilizes a belt with 3 electrodes positioned in a non-standard position for creating a rhythm strip which can be wirelessly transmitted. This application does not disclose the proper method of acquiring the standard 12 lead ECG using the accepted standards setforth by Einthoven, Goldberger and Wilson.
US patent application No. 2009/0264782 of Perlman discloses a method of positioning sensors to derive synthetic composite electrocardiac signals from special sensors not positioned in the standard anatomical positions. However, this application does not disclose the measurement of the standard 12 lead ECG from the electrode placement as setforth by Einthoven and Goldberger nor the simultaneous acquisition of a rhythm strip which displays one or more views of a 12 lead ECG over time which can thus show changes in heart rhythm over time.
US patent application No. 2010/0069735 of Berkner discloses a non-conventional method of deriving a 12 lead ECG with a fewer number of electrodes and by progressively moving a handheld electrode to various locations on the body. To overcome positioning errors, it also discloses the need to calibrate electrode positions and an electronic positioning system without stating accuracy or performance. It also indicates detection of possible signal quality of one roving precordial electrode which is moved across the chest. However, this method is very prone to errors due to mispositioning of the electrodes plus the errors in recalculation and derivation of a 12 lead ECG. Moreover, it does not suggest the simultaneous detection of the quality of all the six precordial and 3 limb contacts necessary for the standard 12 lead ECG. While this application discloses the use of handheld electrodes without revealing the level of noise which is typically induced through the use of handheld electrodes and which is typically not encountered by using a stretchable belt to hold that electrodes in contact without utilizing the muscles of the hand and arm. The use of handheld electrodes and precise positioning by a non-medical user when experiencing acute symptoms of a heart attack is problematic and can lead to measurement errors.
US patent application No. 2011/0105928 of Bojovic et al disclose a wearable belt or belts with electrodes that position a limited numbers in a non-standard orthogonal position so a 12 lead ECG can be calculated and derived from 3 monitoring leads. However, the positioning of these electrodes are not the accepted positions for the standard 12 lead ECG as set forth by Einthoven, Goldberger and Wilson. Moreover, reconstruction of 12 lead ECGs have errors due to the algorithm process and such errors are well described in literature. To minimize errors, one method that has been in this disclosure, is to calibrate the data from the non-standard placement of this limited electrode device by simultaneously utilizing a standard clinical 12 lead ECG machine. The differences in the 12 lead ECGs obtained between the two devices are preserved and corrections are applied when future transmissions are made from the non-standard, limited electrode device in order to enhance the construction of a representative 12 lead ECG. Although this method may help to minimize some errors in the derived ECG however it is not the a clinical 12 lead ECG obtained from the standard anatomically positioned electrodes prescribed locations as set forth by Einthoven, Goldberger and Wilson. Therefore, such an arrangement may produce model and computational errors in the reconstruction of the standard 12 lead ECGs. This method requires a calibration procedure which is not only inconvenient for users but adds unnecessary additional costs. Furthermore, a wireless access point is disclosed to which the ECG device transmits, but this application does not utilize the capabilities of a mobile device such as a smartphone to retransmit the data to a remote location nor does it suggest the convenient display of the 12 lead ECG report or instructions, contact quality, etc. on the access point.
U.S. Pat. No. 4,608,987 of Mills discloses a vest of multiple sizes small, medium, large, etc. that is worn over the chest, back and shoulders that does position the electrodes in accordance with the standard 12 lead ECG electrode placements and is coupled with an acoustic device for telephone transmission to a remote location, however it does not suggest reducing the size of the vest to be a compact belt for portability and compact storage nor does he suggest a digital wireless means to transmit to a remote location eliminating possible acoustic noise.
US patent application No. 2005/0165319 of Brodnick et al discloses a method wherein a wireless phone establishes ECG data communication while in voice contact to transmit. The ECG signals are acquired through the use of a standard clinical ECG machine and a plurality of electrodes by someone with medical knowledge at undisclosed body locations and the data is transmitted to a remote location via internal wireless communication device such as a wireless telephone or connected to an external wireless module for transmission to a remote location. Although this application does suggest using a 12 lead clinical ECG machine that is used in hospital, clinics, etc. to acquire and interface with his device, he does not suggest any method for properly positioning electrodes for obtaining the standard 12 lead ECG data nor any means to transmit the data wirelessly using low power to a local cellular device (e.g., a smartphone) for retransmission to a remote facility. Nor does he suggest how such a device could be made in a small compact form to be easily carried by a user or be applied by the user to properly position the multiple electrodes for a standard 12 lead ECG without errors.
US patent application No. 2010/0124920 of Feher discloses a way to receive Bluetooth ECG signals and transmit to a remote location. However, this application does not specifically disclose a concept of displaying a standard 12 lead ECG nor a display of a representation ECG signals on the receiving/transmitting device itself.
US patent application No. 2008/0234592 of Lim et al discloses a handheld cardiac monitor with externally mounted electrodes. This device is a handheld box with finger electrodes on the housing. For lead I, the left and right hand fingers touch the electrodes. For lead II, the right hand finger can touch one electrode and the other left electrode can be held to the abdomen or the electrode can be removed from the box as it is extendable and positioned in the lead II position. There is no description or claim for obtaining a standard clinical 12 lead electrocardiogram. Moreover, it does not disclose a method for internally storing an electrode in a compact manner. Although it is disclosed that one terminal may also be an “extendable and retractable” lead relative to the housing, however no details of the manner of storage or retraction are revealed and thus the statements are too vague.
U.S. Pat. No. 7,266,405 of Alroy et al discloses a disposable, adhesive array that is not reusable nor is it always attached to the device which can be a problem in an emergency situation as there is no guarantee that this type of detachable array would always be immediately present for use with an electronic device particularly in an emergency situation. This array has at least 9 electrodes with moisture based electrode gel that must retain moisture in storage and is available in multiple sizes to accommodate gender and chest sizes.
In the prior art, U.S. Pat. Nos. 5,339,823, No. 5,465,727 and US patent application No. 2003/0187363 disclose a method and apparatus for a personal device to be used by an individual without any special medical training to capture and transmit a standard 12 lead electrocardiogram. These patents disclose the use of two flying electrodes, one for the right arm (RA) and the other left leg (LL). In emergency and routine use, it is possible to transpose these electrodes and thus acquire an erroneous 12 lead electrocardiogram. Further disclosed is a method of transmitting the ECG over a telephone by frequency modulating (FM) an audible carrier signal and acoustically coupling the sound to a telephone for transmission to a remote receiving location. FM acoustic device systems of this type however suffer from interference caused by local ambient sounds at the telephone as the signal being coupled to the phone. Further, any real-time changes in propagation time over the telephone system can affect the FM signal as received. The result of these transmission conditions adversely manifest as noise on the resulting ECG tracing at the receiving site.
However, although some of these prior art ECG devices are capable of transmitting data to remote medical data center, there still exists a need for a device that can be quickly and accurately applied to obtain a clinical 12 lead ECG and rhythm strip report as setforth by Einthoven, Goldberger and Wilson (i.e., the gold standard). There also still exists a need for such a system which is reliable in use and is user-friendly. There further exists a need for a personal ECG device which can be used in combination with existing portable computer based communication devices (e.g., a mobile cellphone or a smartphone) for enhancing the interaction between the remote medical data center the personal ECG device and the user itself.
It is an object of the present invention to overcome the drawbacks of the personal prior-art standard 12 lead ECG devices and to fulfill the aforementioned needs. The present invention is particularly aimed at ill, people or patients known to suffer from cardiac problems, patients recovering from a surgical intervention or cardiac episode, patients who are experiencing symptoms of arrhythmia, heart attack, ischemia, etc.
It is another object of the present invention to provide a system which is capable of remotely communicated with a data center.
It is yet another object of the present invention to provide a system which is capable of locally displaying ECG related activity information to the user including the quality of the electrode contact and other relevant information (e.g., guiding and instructions for the user during and/or after the use).
Other objects and advantages of the invention will become apparent as the description proceeds.